1054 - Unknown column 'final_price' in 'order clause'

select p.products_id, products_weight, p.products_quantity, p.products_model, pd.products_name, pd.products_description, p.products_image, p.products_price, p.products_tax_class_id, IF(s.status, s.specials_new_products_price, NULL) as specials_new_products_price, p.products_date_added, m.manufacturers_name from products p left join manufacturers m on p.manufacturers_id = m.manufacturers_id left join products_description pd on p.products_id = pd.products_id and pd.language_id = '1' left join specials s on p.products_id = s.products_id where p.products_id not in(688, 171, 1455, 1528, 1471, 1176) and pd.products_name like 'Q%' AND p.products_status='1' order by final_price , pd.products_name limit 0, 50